1. Field of the Invention
The present invention relates generally to systems and methods for encryption, and more particularly for multimedia encryption.
2. Discussion of Background Art
Transmission of audio and video signals, such as video conferencing and security surveillance signal, across both local and wide area networks is becoming more and more commonplace in today's globally interconnected internet driven economy. In such applications, encryption is often required for protecting and authenticating such multimedia signals as they travel over unsecured networks. For instance, corporations often exchange business sensitive information during such conferences which must not be intercepted. Additionally, multimedia information from networked security camera systems must be authenticated and protected from unauthorized monitoring.
A degree to which encryption authenticates and protects multimedia data depends on the encryption schema used, an encryption key length, the predictability of the encryption key, and how the encryption keys are protected. Typically, encryption keys are generated by hashing algorithms from random number seeds provided by a source which hopefully provides random number seeds. Random number seeds, however, are extremely difficult if not impossible to generate using algorithmic methods on digital computers, since algorithms executing on digital computers are by nature deterministic. As a result, various external chaotic sources have been used to generate the random number seeds.
Examples include methods described in U.S. Pat. No. 5,732,138 entitled, “Method For Seeding A Pseudorandom Number Generator With A Cryptographic Hash Of A Digitization Of A Chaotic System,” by Noll et al., and U.S. Pat. No. 5,774,549 entitled, “Method And Apparatus That Processes A Video Signal To Generate A Random Number Generator Seed” by Jakob Nielsen.
Noll discusses generating seeds by applying a hashing algorithm to a digitized chaotic system. Chaotic systems mentioned include clouds moving in the sky, ocean waves crashing on a shoreline, and nodules moving within a “lava-lamp.” A weakness of the Noll system, however, is that in his preferred embodiment, new seed generation depends upon using dedicated input devices to monitor “real-world scenes,” such as a video camera monitoring a lava-lamp, in order to obtain the necessary chaotic input for eventual random number generation.
Nielsen also requires dedicated input devices, such as a video camera. Nielsen monitors “live” scenes with a video camera and then generates seeds from pixel changes within sequential frames of video data. A weakness of the Nielsen system is that new seeds are not generated when motion within a monitored scene stops.
In response to the concerns discussed above, what is needed is a system and method for multimedia encryption that overcomes the problems of the prior art.